One heretofore known method for applying a label to a container comprises wrapping a length of plastic material about the container, bonding the overlapped ends of the length of material, and thereafter shrinking the sleeve that has been formed. This technique is illustrated, for example, in U.S. Pat. Nos. 4,567,681, 4,574,020 and 4,662,965. In another method, a separate sleeve is first formed and then transferred onto the container. The container with the sleeve is then heated to shrink the sleeve about the container. In these methods, the overlapped ends are bonded by heat fusing, solvent or adhesive. The sleeve technique is illustrated, for example, in U.S. Pat. Nos. 3,843,316, 3,959,065, 4,444,613 and 4,496,409.
Among the objectives of the present invention are to provide an improved method and apparatus for forming a shrinkable sleeve and applying it to a container by heat sealing wherein the method and apparatus comprise improved steps and apparatus for forming the sleeve about a mandrel and for transferring the sleeve from a forming mandrel onto a container; wherein the apparatus will handle thin and flexible materials at high speeds; and wherein the transfer of the sleeve to the container occurs over a short overlapping path of the mandrel and container, thereby permitting the sleeve forming portion of the apparatus to be used more efficiently for forming sleeves at high speeds.
In accordance with the invention, a method and apparatus are provided for forming a shrinkable sleeve of plastic material and applying it as a label to a glass or plastic container. The plastic is fed from a source, cut to successive lengths, wrapped about successive mandrels and sealed to form the sleeve. Thereafter, each sleeve is moved from its associated mandrel onto an overlying container. The mandrels are circumferentially positioned on a turret, and a combined heat seal bar and tucker bar assembly is associated with each mandrel to bond the overlapping ends of each severed length of plastic material to one another. A stripper transfers each sleeve that has been so formed from a position on its mandrel axially onto an overlying container while the path of the container overlies the respective mandrel for a portion of its movement by the turret.